President Dmitry Medvedev and former Soviet leader Mikhail Gorbachev led Russian tributes to Polish President Lech Kaczynski in Moscow (video). The Russian air traffic controller Pavel Plusnin, who was speaking to the crew of the Tupolev 154 before it crashed, says that a language barrier exacerbated difficult flight conditions, and the former Polish prime minister suggests that Kaczynski’s insistence that the pilot land the plane was to blame for the crash.  The Times looks at this week’s thaw in Russian-Polish relations and the conspiracy theories surrounding the event, and suggests that Russia ‘should invite Polish experts to take part in, and witness, every aspect of the investigation‘ to dispel suspicion.  Russia’s top leaders (and their wives) have released their income declarations for the second year in a row, meeting disbelief from oppositions politicians and critics – the official records show that Prime Minister Vladimir Putin made $134,000 last year against Medvedev’s $113,774, both apparently banking less than Natural Resources Minister Yury Trutnev and Deputy Prime Minister Alexander Khloponin.  In a US interview, Medvedev praised the work of Putin’s premiership, but complained about journalists questioning the relationship between the two. ‘And how does the relationship work between Mr. Obama and Mr. Biden?‘